1. Field of the Invention
The present invention relates to a TFT structure; specifically, it relates to a TFT structure for use in a TFT liquid crystal display.
2. Descriptions of the Related Art
In recent years, flat panel displays have gradually replaced conventional cathode ray tube displays. Current flat panel displays include: organic light-emitting diodes displays (OLEDs), plasma display panels (PDPs), liquid crystal displays (LCDs), field emission displays (FEDs), etc. An essential component of these flat panel displays is the thin-film transistor (TFT), which controls the on and off state of each pixel.
Stability is important to maintain during the panel manufacturing process to ensure good product quality and enhance manufacturing yield rates. However, during the manufacturing process, varying circumstantial conditions can cause the manufacturing parameters to deviate, resulting in electrical characteristic deviation in each TFT on the panel. For example, a parasitic capacitance of each TFT presents different distributions depending on the different areas of the panel. Because parasitic capacitances can occur all over the panel, non-uniform distributions of the parasitic capacitances will cause non-uniform distributions of the voltage jumps, resulting in the flickering of the screen.
To generally suppress the screen flickering, a compensating capacitor connected with the TFT has been designed to neighbor the original TFT for eliminating the effect of the TFT parasitic capacitance caused by the manufacturing process deviation. However, adding the compensating capacitor on the panel takes up space needed for lighting, and decreases the aperture ratio (i.e. the ratio between the pixel lighting area and total pixel area) accordingly. Moreover, a large compensating capacitor should not be used because it may result in an over range of the voltage jump.
In view of the above-mentioned issue, it is essential for the industry to provide a transistor structure for effectively reducing the area occupied by the compensating capacitors in circuit layouts.